Wifi keeps stopping broadcast

My wifi keeps stopping broadcasting a signal.

The internet connection seems to be fine. The app says I'm connected, my internet is "booming." I have had xfinity for about a month and have had no significant issues. Today, my wifi connection keeps dropping. It is not the internet connection. It is the wifi broadcast.

I have restarted my modem several times. I have done this both by unplugging and restarting in the app. 

Sometimes after a restart, the wifi signal will broadcast, let me connect, and then drop again almost immediately. Sometimes after a restart, it won't broadcast the signal at all.

The only option I've been given for customer service is to have a technician come out, at *my* expense. This is a failure of xfinity equiment. I am not interested in paying them to fix their own faulty equipment.

Most of the solutions I've found for this same problem in these forums seems to be a faulty router and xfinity replaces it, and things work fine again. Some folks have taken their modem/router to an xfinity store and changed it out. How do I go about just getting replacement equipment?